1. Field of the Invention
The present invention relates to a process for the selective removal of carbonyl sulfide from a gas mixture also containing hydrogen sulfide.
2. Description of the State of the Art
In the purification of gas mixtures, e.g., natural gas, by absorption to remove minor amounts of undesirable contaminants, it is desirable for highest gas purification to regenerate the absorbent to expel as much as possible of the contaminants to provide the leanest possible absorbent for recycle.
In conventional methods of purification of gas mixtures containing carbonyl sulfide and hydrogen sulfide, both gases are cosorbed by the absorbent and in the desire to provide lean solvent recycle both are expelled to the greatest extent possible on regeneration, usually by steam stripping. This is true even when the gas to be treated comprises a major amount of or is principally hydrogen sulfide gas.
It is desirable to selectively remove carbonyl sulfide from a gas mixture also containing hydrogen sulfide with reduced cosorption of large amounts of hydrogen sulfide. It is also desirable to reduce any steam requirements for regeneration of sorbent solution.